It's a minimum security Federal Prison Camp where inmates can escape by simply waking away. Even when convicted, these traitors don't do hard time.
I cannot find confirmation on this, but I suspect the reason for the visit is that in-person visits are less likely to be monitored and "safer" for discussing illegal or incriminating topics. Can't imagine any other reason for Donnie Jr to go there in person.
As I understand it, the warden as the authority to add such monitoring, but regulations only require supervision to the degree of preventing contraband from being passed between visitors and inmates. While I found no confirmation for this, I cannot imagine the warden of a minimum security facility wanting to spend a portion of their budget on this level of surveillance.